Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider
registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.

Yeah, I was wondering about that. I don't have the numbers in my head, and I'm honestly too lazy to look them up just now (Terraria and rum are calling), but I do know that sauropods were around for a good long time--on a geologic scale--before the dinosaurs had their bottleneck. We know the Cretaceous was pretty hot, if nothing else from the ocean anoxic events. It's interesting that sauropods contributed, though. I wonder how cattle herding would impact our plant.

Yeah, I was wondering about that. I don't have the numbers in my head, and I'm honestly too lazy to look them up just now (Terraria and rum are calling), but I do know that sauropods were around for a good long time--on a geologic scale--before the dinosaurs had their bottleneck. We know the Cretaceous was pretty hot, if nothing else from the ocean anoxic events. It's interesting that sauropods contributed, though. I wonder how cattle herding would impact our plant.

I'm more curious of methane turnover mostly because I'm not aware of what may utilize methane other than local bacteria, other than that aside from conversion to H20 methane seems to be reuptaken in water and soil. Dinwar you'd probably know more but how much terrestrial methane would be reuptaken via oceans and removed from the atmosphere? at least evident on a geological timescale (I'm not sure if eutrophicated lakebeds offer any clues to it either)

__________________"If I actually believed that Jesus was coming to end the world in 2050, I'd be preparing by stocking up on timber and nails" - PZ Myers

Yeah, I was wondering about that. I don't have the numbers in my head, and I'm honestly too lazy to look them up just now (Terraria and rum are calling), but I do know that sauropods were around for a good long time--on a geologic scale--before the dinosaurs had their bottleneck. We know the Cretaceous was pretty hot, if nothing else from the ocean anoxic events. It's interesting that sauropods contributed, though. I wonder how cattle herding would impact our plant.

It would all come down to a straight shot at bio mass. Has anyone ever come up with herd sizes for critters like triceratops etc

In NZ, farming is the biggest contributor to greenhouse gases, emitting nearly half of the greenhouse gases. energy is close behind, which includes power generation and vehicle emissions.link to official website
so yes, cattle have a big effect.

__________________"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
-- Albert Einstein
"Never memorize something that you can look up."
— also Albert Einstein

I'm more curious of methane turnover mostly because I'm not aware of what may utilize methane other than local bacteria, other than that aside from conversion to H20 methane seems to be reuptaken in water and soil. Dinwar you'd probably know more but how much terrestrial methane would be reuptaken via oceans and removed from the atmosphere? at least evident on a geological timescale (I'm not sure if eutrophicated lakebeds offer any clues to it either)

It simply oxidizes in the air, too.

__________________For what doth it profit a man, to fix one bug, but crash the system?

Dinwar you'd probably know more but how much terrestrial methane would be reuptaken via oceans and removed from the atmosphere?

I'm not sure. The only thing I've really heard concerning methane and oceans is about clatherates, which are pertty poorly understood. Currently they seem to think they're biogenic, so they're no help at all. I do know (from "Life as we Do Not Know It" and "The Gaia Hypothesis", as well as the references therein) that methane has a pretty short residence time in the atmosphere. It degrades rather quickly--certainly on scales humans would be cognazent of (as opposed to multi-millenial scales).

Originally Posted by MattTheTubaGuy

so yes, cattle have a big effect.

In terms of absolute methane produced, I'll happily agree. However, I'm not sure that's sufficient to answer this question. The real question is, how much has methane production per pound of biomass changed over time? There's a lot more cows out there than there ever were sauropods, but sauropods were so much bigger than cows that I'm not sure how it ballances out.

Originally Posted by MG1962

It would all come down to a straight shot at bio mass. Has anyone ever come up with herd sizes for critters like triceratops etc

Yes, but the results are inconoclusive. It's hard to evaluate this sort of thing. Merely finding bones together doesn't indicate they traveled together--Rancho La Brea is proof of that. And fossil trackways may or may not help--after all, it's entirely plausible that a bunch of individuals were in the same area at the same time (squirrels and rabbits, for example, do this). Sauropods are even worse, because they apparently utilized a number of herd strategies, meaning there's no one answer. And given the rarity of good, solid evidence for ANY herd behavior, that means we may never know the particular behavior of particular species.

"Oxidation" does not equal ignition--if it did, rust could only happen at temperatures at which steel burns. It doesn't even have to do with oxygen, necessarily. Oxidation is the loss of electrons during an oxidation/reduction reaction, nothing more. It frequently occurs during combustion--oxygen is a VERY vigorous oxidizer--but to say that all oxidation reactions require high heat is like saying all running must be done at the Olympics.

"Oxidation" does not equal ignition--if it did, rust could only happen at temperatures at which steel burns. It doesn't even have to do with oxygen, necessarily. Oxidation is the loss of electrons during an oxidation/reduction reaction, nothing more. It frequently occurs during combustion--oxygen is a VERY vigorous oxidizer--but to say that all oxidation reactions require high heat is like saying all running must be done at the Olympics.

You're absolutely right, I was talking drivel. Must learn not to post in haste in the early hours.

By estimating 44,000 lbs per mid-sized sauropod and "a few dozen"(?) per square mile, the authors come up with a figure of 520 million tons of methane per year, meaning they outfarted modern ruminants - mustering up a measly 50 to 100 million tons per year - by at least FIVE to one!

You're absolutely right, I was talking drivel. Must learn not to post in haste in the early hours.

No worries. It was actually interesting to look into, which is why I come here in the first place.

Originally Posted by blobru

By estimating 44,000 lbs per mid-sized sauropod and "a few dozen"(?) per square mile,

Yeah, that's going to be a nightmare....The issue is that I seriously doubt sauropod herds were evenly distributed. I can only imagine that there would be areas of denser sauropod populations, and areas of less-dense populations.

Of course, all of this assumes that the flora is constant. It's not--the Mesozoic flora was wildly different from the Cenozoic flora, to the point where it's hard to imagine what it was like back then. It could be that the increased methane was utilized as a resource by more plants (well, their symbiotes, anyway) than today, making local residence time much, much smaller. It woudl be interesting to see if methane-consuming plant/microbe symbiotes were more prevelant in areas of denser sauropod concentrations.

I'm not sure. The only thing I've really heard concerning methane and oceans is about clatherates, which are pertty poorly understood. Currently they seem to think they're biogenic, so they're no help at all. I do know (from "Life as we Do Not Know It" and "The Gaia Hypothesis", as well as the references therein) that methane has a pretty short residence time in the atmosphere. It degrades rather quickly--certainly on scales humans would be cognazent of (as opposed to multi-millenial scales).

Right but I meant was how much methane wasn't degraded in the atmosphere but reuptaken by other organisms if such a means is possible. We study atmospheric concentrations via lake eutrophication strata (not that it's actually a strata...) in rock; thought that could apply to methane too.

__________________"If I actually believed that Jesus was coming to end the world in 2050, I'd be preparing by stocking up on timber and nails" - PZ Myers

In NZ, farming is the biggest contributor to greenhouse gases, emitting nearly half of the greenhouse gases. energy is close behind, which includes power generation and vehicle emissions.link to official website
so yes, cattle have a big effect.

But wouldn't this be true anywhere? I mean even on a desert Island "something" is the leading cause of greenhouse gasses. That doesn't exactly prove it's a problem.

Right but I meant was how much methane wasn't degraded in the atmosphere but reuptaken by other organisms if such a means is possible.

I know--I just couldnt' find anything to answer your question.

One thing that I DO know is used at times is low delta-C13 values. Methane seems to be overwhelmingly biased towards lighter (I think) carbon atoms. We can tell when methane clatherates, at least, cut loose. I honestly don't know if non-marine methane has a similar bias.

Ice cores may be a good place to look....after that I just don't know, the residence time is so small it's very hard to detect.

Originally Posted by BravesFan

But wouldn't this be true anywhere? I mean even on a desert Island "something" is the leading cause of greenhouse gasses. That doesn't exactly prove it's a problem.

You're right, in that there has to be some maximum contributer (or multiples, in the case of ties). However, that's not the issue of concern here. It's more a question of "How much does this one source contribute?" And the comparison to vehicles and energy is apt, as (at least for us Yankees) we're so used to thinking of energy as The Source for all greenhouse gases.

I wonder how rigorous the calculations are. There is a pretty wide range in the amount of methane released per pound of modern ruminants (cows produce 5x what wallabies produce, for instance) and it seems not unlikely that there was similar variation in sauropods. I'm also wondering about the few dozen 22 ton sauropods per square mile bit. Per square mile of Earth's surface, on average? Per square mile of optimal habitat? That number just seems high to me. I'm trying to find an estimate of historical elephant populations for comparison, but not having much luck.

__________________Sandra's seen a leprechaun, Eddie touched a troll, Laurie danced with witches once, Charlie found some goblins' gold.
Donald heard a mermaid sing, Susie spied an elf, But all the magic I have known I've had to make myself.
- Shel Silverstein

But wouldn't this be true anywhere? I mean even on a desert Island "something" is the leading cause of greenhouse gasses. That doesn't exactly prove it's a problem.

Nor was there any suggestion that it is a problem. It's simply a fact. Ruminants can out-produce the greenhouse gases of four and a half million people living a modern developed lifestyle at low density. It takes a heck of a lot of ruminants, true, but there it is.

That's a problem in the sense that the methane represents wasted food, and efforts are being made to solve that.

__________________It's a poor sort of memory that only works backward - Lewis Carroll (1832-1898)

God can make a cow out of a tree, but has He ever done so? Therefore show some reason why a thing is so, or cease to hold that it is so - William of Conches, c1150

Yes but little of it has been published or digitised; it's mostly still confined to the original bar-mats, napkins, and backs-of-envelopes.

In my experience that's sadly because once the liquer wears off the calculations look much less rigorous or supportable. Alcohol is great for helping geologists think (I actually once successfully argued in favor of someone taking up drinking because controlled randomness in thought processes is beneficial in certain stages of conceptualization ), but the culling process it necessitates can be a pain in the rear. And the ego. And occasionally, in my experience, the libedo....